A 2-year, open-label followup was performed on 130 obsessive-compulsive patients who were responders to a previous 6-month treatment with clomipramine (150 mg/day), fluoxetine (40 mg/day), or fluvoxamine (300 mg/day). Continuation treatment with the same daily dose was compared to continuation with half doses or to discontinuation of pharmacotherapy. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Clinical Global Impressions (CGI) scale were used every 3 months, or whenever a worsening of symptoms was experienced. Maintenance treatments were found significantly superior to discontinuation in preventing relapses, and no differences in efficacy were found between full and half doses. A comparison of the three subgroups of patients who were withdrawn from drug therapy failed to demonstrate any statistical difference.